Pump



Feb. 21, 1933. p Q, DORER 1,898,348

PUMP

Filed Sept. 8. 1951 2 Sheets-Sheet l www ^ swat INVENTOR @www P. O. DORER Feb. v21, 1933.

PUMP

Filed Sept. 8. 1931 2 Sheets-Sheet 2 Patented FAB. 21, 1933 UNITED STATES `1 ATE NT OFFICE ramos oT'ro nonna, or LoNDoN, ENGLAND, AssTGNoR on' oNE-HALE 'ro ALLAN GORDON SMITH, F

LONDON, ENGLAND PUMP Application led September 8, v1.931, Serial No. 561,594, and in GreatBritain October 21, 1930.

This invention relates to pumps such as are used as fuel-pumps in motor-vehicles.

The invention is concerned with the type of pump in which the delivery-stroke is produced by compressible means (for example a spring, hereinafter referred to as the delivery spring) on one side of the pump-diaphragm overcoming the pressure of the liquid in the pump-chamber, and in which a lever directly connected to the pump-rod is power-actuated to overcome said compressi-- ble means and produce a suction stroke.

It is an object of the present invention to provide an improved pump in which the delivery of fluid from the pump will be varied in accordance with the consumption o such fluid. Another object of the invention is to provide a simplified construction of such pumps which will be comparatively sil'ent in operation.

According to the present invention, there is provided'a pump of the type above referred to, wherein the pivot of the power-actuated operating lever (which produces the suction stroke) is resiliently supported, for example in the pump-casing. The purpose of supporting the pivot resiliently is to ensure that the end of the lever is always in contact with the power-actuated means which drives it.

According to a further feature of the invention, the pivot of the lever is supported by a link which is pivoted 'on the casing at one end and resiliently (for example by a spring) connected to the casing at the other end.

According to a further feature of the in vention the pivot of the lever may be mounted in a fixed slotted member (for example a 40 slot in the pump-casing) and may be urged towards one end of the said slot by a springpre'ssed saddle.

Embodiments of the invention will now be described with reference to the accompanying drawings, whereon:

Figures 1 and 2 are a sectional elevation and end view respectively of a fuel-pump for a motor vehicle of the class with which the present invention is concerned:

Figure 3 is a sectional elevation of the pumpshown in Figure 1 with the operating parts 1n 'a different position corresponding to conditions described hereinafter:

Figure 4 is a form of support for the pivot of the operating lever in accordance with the present invention and applied tothe class of pump illustrated in Figs. l, 2 and 3.

In Figures 1 and 2, inlet and outlet valves 1( and 11 for the pump chamber 9 are provlded in the pump-casing 12 and so disposed 60 with respect to a iexible diaphragm 13 that, on movement of the diaphragm in the downward direction, fuel is drawn through thev inlet valve 10, and on movement of the diaphragm in the other direct-ion fuel is delivered through the outlet valve 11. The fuel entering by the inlet valve may rst pass through a fuel filter. and this filter may conveniently be connected to the casting 14 `which, together with the casting 15, forms the pump-casing 12. The filter is not shown in the drawings. The diaphragm 13 is normally deformedby a delivery spring 16 into apositionwhich corresponds with the end of the delivery-stroke of the pump.

A connecting-rod 17 is secured to the diaphragm by the nut 18 and washers 19 and 2O and extends through guides 21 formed in the pump-casing to the .operating lever 22. The connection between the operating lever 22 80 and the connecting rod 17 is by way of the pin 23 on the connecting rod and the bifurcated end 24 of the lever.22.

The lever 22 pivots about a pin 25 fixed in the pump-casing and engaging a slotted part i 26 on the lever. A light compression-spring 27 acts on the lever .22-directly above the slotted part 26, and, under normal conditions of supply as shown in Figure 1, is completely compressed to provide a base on which the lever can pivot. A cam 28 driven, for example, from the engine bears on the end 29 of the lever`22 and produces the suction stroke. The delivery strokeis effected by the spring 16 deforming the diaphragm 13 95 to overcome the pressure of the fuel in the pump-chamber 9.

In operation, when there is no substantial pressure in the pump-chamber, the delivery spring 16 holds the diaphragm 13 in the full- 100 in position. The cam 28 acting on the end 29 of lthe lever 22 rocks the lever about its pivot 25 and since the spring 27 is completely compressed the pump-connecting-rod 17 is pulled down and deforms the diaphragm 13 to draw fuel through the inlet valve 10 into the pumpchamber 9.

If, however, as shown in Figure 3, the pressure in the pump-chamber 9 is greater than the urge of the delivery spring 16, the pumpconnecting rod 17 will be moved through a distance proportional to this pressure. The slot-26 will also move along the pin 25 to a new position since the end 29 is always in contact with the cam 28 and the pin 25 will still act as the pivot for the operating lever 22 but part of the lift of the cam will be taken up in lost motion of the slot 26 againstthe urge of the spring 27 with respect to the pin 25 until the pin isr in the lower end of theslot asl shown in Figure 1. In this way, a suction-stroke, limited in accordance with the increased pressure in the pumpchamber 9, will be produced.

In the extreme position when the pressure in the pump-chamber is such as to deform thc diaphragm 13 into a position correspondingI with the end of the suction stroke, the lift of the cam will be entirely taken up in compressing the spring 27 and in moving the slot 26 with respect to the pin 25; that is to say the lever 22 will pivot, under these conditions, about the pin 23 on the pumpconnecting-rod 17. The above description of Figs. 1, 2 and 3 relates to the class of pump with which the present invention is concerned. In Fig. 4 of the drawings the construction of pump which forms the subject matter of the invention is illustrated and '1n this figure the pivot of the lever 22 is constituted by a pin 30 carried by a link 31 pivoted at 32 to the pump-casing 12. The purpose of the link 31 is to keep the nose 33 in its correct position in relation to the spring 27. Since the lever 22 is supported by the pump rod through its bifurcated end and is in sliding contact with the cam 28 it is necessary to provide a guide for the nose 33. A spring 27 bears on a nose 33 formed on the lever 22. The operation of this modified form is the-same as the slotted lever confrom the said end by the cam 28 bearing on the end 29 of the lever.

Moreover, all mechanical inversions and/or equivalents of the construction hereinafter claimed are held to lie within the scope of the invention as set out in the appended claim.

I claim A liquid-pump comprising in combination a casing, a pump-chamber formed in the said casing, inlet and outlet valves for the chamber, a pump-diaphragm, compressible means on one side of the said diaphragm for producing a delivery stroke, a pump-rod, a lever, a pivot point for the lever intermediate the ends thereof, a pivotal connection between the said lever and the said pump-rod whereby the pump-rod supports one end of the said lever, a power-actuated part supporting the other end of said lever and operating on it to overcome the said compressible means and produce a suction stroke, a link, a pivotal connection between the said link and the pump-casing, a pivotal connection between the said link and the said lever to constitute a guide for the pivot of the lever, and a resilient member bearing on the said pivot point of the said lever, the resilience of the said member being such that when stressed to a predetermined limit it exerts such a forcel that an effective fulcrum is provided for the lever.

In testimony whereof I affix m signature.

PRIMUS OTTO ORER.

struction above described since the pivot of 

